264 Mr. Horace A. Byatt on 
It is due to the suggestion of Professor Poulton that 
this would be an excellent opportunity to ascertain what 
numerical relation the Pseudacrva bears to its model 
chrysippus that this paper has been hastily prepared in 
the Hope Department at Oxford before my return to 
Central Africa. 
The country in which Kayambi is situated does not 
differ greatly from the rest of the plateau to the W. 
of Lake Nyassa and N.E. Rhodesia. Large stretches 
of undulating plains, covered with thin scrubby bush 
or dense tall grass, are intersected at intervals of 5-20 miles 
by streams and rivers. In the latter months of the year, 
when these insects were mostly collected, these plains 
are bare, dry, and dusty, grass and bush being burnt up 
by the annual bush-fires: and only along the streams is any 
verdure found. Pere Guillemé describes the soil as fertile 
along the course of the rivers, but elsewhere the district 
is generally poor and sandy, and for this reason sparsely 
inhabited, and he remarks on bush-fires being the cause 
of the general scarcity of insect-life except along the 
water-courses, where the vegetation is untouched by fires, 
and where forest-giants, trailing creepers, and tree-ferns 
flourish. 
The altitude of Kayambi is about 3950 ft. above sea- 
level; and its position roughly 9° 20'S. and 31° 50’ E., 
some two days’ march from Fife, and three from Abercorn, 
on the Nyassa-Tanganyika plateau. 
The respective numbers and species in the collection 
were worked out in the Hope Department and are stated 
in tabular form below :— 
SPECIES. g 9 
Limnas chrysippus : . | 288 79 | 367 
| do. do. var. dorippus 8 4 12 
_ Pseudacrea pogger : : -— — | 17 
| Hypolimnas misi pps. 36 7 ; 45 
| a » & var. Maria 2 
Total number in group 441 
From this table it will be seen that Pseudacrea pogger 
is by no means so rare as has been hitherto supposed ; 
its proportion to Z. chrysippus is no less than 4°72 per 
cent. The dorippus, K1., or klugii, Butl., form of chrysippus 
